Art of refining hydrocarbons



Filed Feb. '29,

A C VOBACH ART OF REFINING HYDROCARBONS Nov. 19, 1929.

Patented Nov.. 19, 1929 l UNITE- STATI-:s

ARNOLDl c. voisAoH, or vvH'I'rINe,l INDIANA, AssIGNoIt To sINoLAIR REFINING 00M- PANY, oF NEW YORK, N. Y.;

PATENT OFFICE A. CORPORATION OF MAINE ART OF REFINING HYDROCARBQNS Application ledFebruary 29, 1928. 'Serial No. 257,945.

This invention relates to improvements in the manufacture of gasoline; more particularly the inventionrelates to improvements in the combined cracking of oil to-.produce gasoline and refining of the cracked gasoline by passage through an adsorptive catalyst in 'vapor phase. i r

When gasoline or a gasoline-containing fraction is passed in vapor phase through an` adsorptive catalyst such as fullers' earth, certain unsaturated constituents suchA as di. olenes, to the extent that they are present, are polymerized to .form higher boiling polymers. This reaction affords a means of separating such'constitu'ents Without' involving 'loss of other unsaturated constituents. This general refining method is applied particularly to gasoline intended 'for use as motor fuel because it makes possible the removal of objectionable`K uns-aturated constituents Withoutl removal of unsaturated constituents of special value as components of motor fuel gasoline. The separation of the polymers produced by the vapor-catalyst Contact is usually accomplished by fractional condensation. liquefaction, either in therening operation proper or in some subsequent fracltionating operation. The separatedl liquefied polymers usually includelight and intermediate oil constituents vas Wellas heavy:

constituents, tars and the like.

As vappliedA to gasoline-containing vapors from cracking operations, this general reflning method is particularly useful because the cracking reaction, particularly when, the oil is subjected to severe cracking conditions,

, usually involves the production of both objectionable and valuable unsaturated constituents. The cracking operation is frequently' carried'out under `severe cracking conditions to increase the concentrationI of valuable unsaturated constituents in thethis general refining method is applied ini creases. .l

The light oil constituents of liquefied polymers separated in carrying out this general refining method' usually include some constituents suitable as components of the gasoline product. The intermediate oil constituents, and sometimes part of the'light oil constituents, usually are suitable as components of stocks to be cracked. Some of the intermediate oil constituents, and'sometimes some This invention rovides apparticularly ad vantageous vcombined cracking and refining operation which includes the separation of heavy constituents from polymers produced in the refining operation, the recovery of constituents suitable-as components of the prod-i luct entrained in liquefied polymers separated in the operation, the return to the crackin-g operatori of all suitable constituents of se'pafI rated liquefied polymers Without return ,of objectionable heavyA constituents tendingto interfere with the cracking operation, the return to thecracki'ng operation of all suitable constituents of separated liqueed polymers 'Without return of "constituents suitable as components of the product avoiding a rial, and the return to the cracking operation lofall suitable constituents entrained in sepatendency toWard-overcr'acking of this matef rated liquefied polymers'. j' Theinvention is.v

particularly useful when there is a. 'large amount* of separated liquefied polymers to be handled, when there is entrainment insejf` arated liquefied polymers of constituents va `uable either as components of the product or as stock to be cracked, and-'when the content, i, of heavy constituents, ta'rl and the like, inn' separated liquefied polymers is high.

According to the present invention, -the charge of these heavy constituents the gasoline-containing vapors are passed through an adsorptivecatalyst in vapor phase, the polymers produced by the vapor-catalyst contact are liquefied and separated from the resulting vapor mixture, either in the refining operation proper or in some subsequent fractionatingl operation, and the separated liquefied polymers are supplied to thel scrubbing'treatment'where light andinterrnediate constituents are vaporized to escape with the gasoline-containing vapors escapingl from the scrubbing treatment and heavy constituents,

tar and the like,'are separated and discharged 'with the' lirst-mentioned heavy constituents without being permitted to return to thel cracking. operation. The l scrubbing treatment operates to separate heavy constituents,

` tar and the like, produced in the cracking oper-ation proper as well as those included in liquefied pol `mers supplied thereto and also `operates to eep theescaping gasoline-containing vapors -free fromsuch constituents from any source. The vvapor mixture escap-l ing from the scrubbing treatment, before being passed vthrough the adsorptive catalyst, 'is with advantage subjected toa refluxing oper-` ation in which 'those constituents heavierthan suitable as componentsof the gasoline product yet suitable as components of the `stock A, supplied to the cracking operation proper are condensed and from which the resulting oil mixture is supplied to the cracking operation. Raw stock to be Vsupplied to the crackingoperation may be supplied to this reiuxing operation and suppliedto the cracking operation proper withthe condensate therefrom. Theintermediate constituents of the liquefied polymers'separated in the rening operation vaporized in -thescrubbingtreatment may be so condensed and returned tothe cracking operationproper with :the condensate from the refiuxing operation. The vaporfmixture escaping from the refiningl operation, either with or without further 'fractionatiom is condensed to forma refined "ventionally, one form of apparatusadapted .'60

Afor carrying out the invention, but itwillbe understood that'the invention can be carried out in-otherand different forms of apparatus.

The apparatus illustrated includes a vapor phase cracking apparatus described more in detail in an application of Harry L. Pelzer,

ing apparatus becauseof thesevcre cracking conditions usually maintained in operation. 4 Referringto the drawings, raw .oil ,or reliux condensatey or a mixture of the two is supplied to the heating conduit 1 through connection 2,- is heated and vaporized and the vapors superheated in the heating conduit, the vapors` are passed through the digesting drums 4 through connection 5 and fromv the last digesting drum are discharged into thelower end of' the scrubbing tower 6 through connection 7. For example, the temperature of the `vapors passing from the heating conduit 1 to the digesting drums 4 may approximate 100G-12000 F., the temperature ofl the vapors passing from the digesting drums 4 to the scrubbing tower 6 may approximate 9501100 F., and the oil may be v supplied to the heating conduit 1 under pressure sufficient to ,force the'oil and oil vapors through the apparatus, the pressure in the scrubbing tower 6v may appoximate -1-3 inches of mercury. -Vapors escape from 'thetower 12 throughconnection 13, either-'up- "wardly ordo'wnwardly through the relining tower 12, and from the refining tower 12 to the condenser 14 through connection 15.

The condenser 15 discharges into receiver l and separator -16 through connection 17. The condensed product is discharged from the receiver 16 through connection 18 and uncondensed vapors and gases through connection `19. Either or both -the `refiux tower 8 andthe fractionating tower. 10 may be bypassed by means of connections' 20 and 21. The' scrubbing treatment carried out in tower 6 may be effected or controlled by the in-4 troduction of raw oil, particularly stock containing heavy constituents not suitable to be supplied to the heating conduit, through connections 22 and 23, by the introductionof condensate from the fractionatingtower 10 through connections 24 and 28, by therecirculationl through the tower of the vheavy /separated material, either before orrafter cooling in cooler 25, through/ connection 26, or by any combination of these means. y The reuxing operation carried out i-n tower 8 may be effected orcontrolled by the introductiono'f raw oil through connections 27 and 28 or by the introduction of condensate from the frwctionating tower 10 throughconnections 29 and 28, or by the introduction of both. The fractionating operation carried out in tower 10 may be `effected or vcontrolled by the introduction of part of the condensed product through connections 30 and 3l or by the introduction of another retluxing medium such as another gasoline fraction through connections 32 and 31. Condensate and any admixed unvaporized raw oil from tower 8 may be supplied to the heating conduit 1 through connections 33 and 2 by means of hot oil pump 34. ,Condensate from tower lOmay be supplied to the heating conduit 1 l through connections 35 and 2 by means of hot oil pump 36. Raw oil may also be supplied directly to the heating .conduit 1 through connections 37 and2. Condensate from tower l0 may be discharged through connection. 38. The heavy material 'separated in the scrubbing tower 6 is dischargedthrough connection 39. A charge of a suitable adsorptive catalyst, for example, fullers earth'A of 40-60 or 60s-80 mesh, is supported upon a foraminous partition in the refining tower 12. In accordance with the present invention, the'polymers -produced by the vaporcatalyst contact in the refining tower 12 and liqueedand separated therein are supplied through connections 40, 41 and 23 to the upper end ofthe scrubbing tower 6 and there are introduced into the vapors in the scrubbing tower, by means of pump 42.

In carrying out the invention in the apparatus illustrated, heavy constituents, tars and the like, unsuitable either as components of the gasoline product or to be returned to the heating conduit are separated in the scrubbing tower 6 and discharged through connection 39 without being permitted to return to the heating conduit, after escaping from the scrubbing tower 6 the gasoline-containing vapors pass through the adsorptive catalyst in the refining tower 1 2 (they may pass first,-

through either or both the reflux tower 8 and the fractionating tower 10), the polymers produced by the vapor-catalysts contact are liquefied and separated from the resulting vapor mixture in the refining operation, the

`,gasoline or .gasoline-containing vapors escape to the condenser 14, thev separated liquefied polymers are discharged through connection 4() and introduced into the upperend of the scrubbing tower 6, heavy constituents of the liqueield polymers so introduced into the scrubbing tower are discharged through connection 39 with the heavy materialseparated from the gasoline-containing vapors from the cracking operation without being permitted to retain to the heating conduit, the rest of the liquefied polymers so introduced into the scrubbin tower are vaporized and the vapors so forme escape with the gasoline-containing vapors from the cracking operation. The vaporized constituents of the liquefied polymers supplied to the scrubbing treatment then are condensed' in tower `8 and 10 with the -corresponding fraction of the vapors from the cracking operation, intermediate constitu-l entsv suitable as components of the stock supplied to the cracking operation are condensed in the reiiux tower 8 and returned to the heating-conduit with the condensate therefrom, other intermediate or light constituents may be condensed inthe. fractionating tower 10, and light constituents suitable as components of the gasoline product pass on with the gasoline-containing vapors to the condenser 14. Vhen used, the fractionating tower 10 may be operated to condense all constituents lheavier than suitable as components of the gasoline product desired so that the conl densate discharged from receiver 16 is' of the required end boiling point. 4

The heating furnace illustrated comprises a fire-box 3 in which fuel is burned, a heating iiue in which the heating conduit I is arranged and a heating chamber in which thedigesting drums 4 are arranged communicating with the fire-box, a fan for recirculating part of the escaping heating gases through the heating flue and the heating chamber and 'for discharging therest through' a stack, and

a fan and heat exchanger arranged in the stack for supplying preheated air to the firebox for combustion, with appropriate connections and dampers as shown.

I claim; In' the combined cracking of oil tol produce gasoline andrening of the cracked gasoline by passage through an a'dsorptive catalyst in vapor phase, the improvement which comprises subjecting the gasoline-containing vapors from -the cracking` operation to a scrubbingtreatment and therein separating passing gasoline-containing vapors escaping? from the refluxing operation through the ad- A sorptive catalyst in vapor phase', separating liquefied polymers produced by the vaporcatalyst contact from the resulting vapor mixture, supplying such separated liqueiied polymers to the scrubbing treatment and therein vaporizing .light and intermediate oil constituents thereof whereby such vaporized oil constituents escape with the gasoline-containing vapors from the scrubbing treatment, discharging the unvaporized heavier constituents of the liquefied polymers supplied to the scrubbing treatment with the firsty (um my name.

mentioned heavy constituents separated in the scrubbing treatment without permitting them to return to the cracking operation, and

condensing in the refluxing operation and returningto the crackin operation with the condensate therefrom lntermediate oil con-` stitutents of the liquefedpolymers vaporized in the scrubbing treatment.- v In testimony `whereof I have subscribed t `ARNOLD c. VOBACH. e '1 

